Many heating and cooling systems are used in all aspects of industry to regulate the temperature of a heat source, wherein the fluid systems are closed loop and are sealed to prevent substantial leakage of working fluid from the system. Existing heating and cooling fluid systems use flexible hoses, gaskets, clamps, and other seals to attempt to provide a sealed environment within the system. However, the material and structural characteristics of these mechanical components cause a slow loss of fluid from the fluid system over a period of time. The loss of fluid occurs due to evaporation as well as permeation of fluid and vapor through the materials of the components and the seals which connect the individual components of the system together. As used herein, permeability refers to the ease at which a fluid or vapor transports through a material.
One example of a cooling system is a system for cooling the engine in an automobile, whereby the cooling system uses rubber hoses, gaskets and clamps. As stated above, the structural and mechanical characteristics of these devices have a high permeability which allows cooling fluid to escape from the system at a high rate. Nonetheless, it is common in the automotive industry for automotive manufacturers to recommend frequent checks of the fluid level in the cooling system and occasional refilling of the lost fluid. The requirement for fluid refilling in automotive applications is tolerated, because of the low cost and high mechanical reliability of the materials of which the components are made.
However, for a closed loop fluid system which regulates the temperature of a circuit in a personal computer, server, or other electronic device, there can be no such requirement for customers to check and refill fluid levels in the cooling systems. In microprocessor cooling systems, replacing fluid which has been lost would be very burdensome and expensive due to the difficulty of dismantling the cooling system and replacing the small scale components. In addition, refilling of fluid in a microprocessor cooling system would cause great potential for equipment failures, safety risks, and loss of data owing to a short circuit caused by spilled fluid. In essence, it is desired that the microprocessor cooling system operate for the entire life of the product without requiring any periodic maintenance. Therefore, containment of the circulating fluid in the cooling system is a design goal in electronic systems cooling equipment, and the use of fluids in computer equipment cooling systems is commercially feasible if there is no risk of fluid or vapor escaping from the cooling system.
Cooling systems using fluids which regulate the temperature of a microprocessor exist in the market. However, the components in these existing cooling systems are made of plastic, silicone and rubber components which are secured together by hose clamps. The permeability and diffusion rates of single phase and two phase fluid through these components into the surrounding environment are unacceptably high due to the materials of which these components are made. The high permeability and diffusion rates of these materials make it almost impossible to prevent escape of the fluid from the cooling system. Therefore, the cooling system is not able to maintain its integrity over the expected life of the system and eventually dry up as well as create humidity within the computer chassis.
What is needed is a hermetic closed loop fluid system for regulating the temperature of an electronic device in a product, whereby the fluid system is configured to prevent significant loss of fluid over the life of the product.